Clinton Anthony John Duffy

• MSc Zoology
• Curator of Marine Biology at Auckland War Memorial Museum

Western Pacific leatherback sea turtles (Dermochelys coriacea) are a priority bycatch mitigation concern due to the projected extinction of the population before the end of the 21st century. The species regularly occurs as bycatch in gillnet and surface longline fisheries. Here, we explore the potential for dynamic ocean management in an emerging h...

Five species of sea turtles are known to occur in New Zealand waters, with the leatherback turtle (Dermochelys coriacea) being the most frequently reported. In New Zealand all sea turtles are protected, but there are currently no fisheries bycatch mitigation measures. We describe fishery captures of leatherbacks from Ministry observer and fisher se...

Aim Climate change is driving biogeographic change globally, including poleward range shifts of species and the increasing abundance of rare species. We examine spatiotemporal patterns in the occurrences of tropical, subtropical and rare marine fishes in Aotearoa New Zealand to determine whether biodiversity change is occurring in this temperate re...

106,107 ✉ replying to A. V. Harry & J. M. Braccini Nature https://doi.org/10.1038/s41586-021-03463-w (2021) Our global analysis 1 estimated the overlap and fishing exposure risk (FEI) using the space use of satellite-tracked sharks and longline fishing effort monitored by the automatic identification system (AIS). In the accompanying Comment, Harry...

This article is a response to Murua et al.'s Matters Arising article in Nature, "Shark mortality cannot be assessed by fishery overlap alone," which arose from arising from N. Queiroz et al. Nature https://doi.org/10.1038/s41586-019-1444-4 (2019).

Cosmopolitan marine pelagic species display variable patterns of population connectivity among the world’s major oceans. While this information is crucial for informing management, information is lacking for many ecologically important species, including apex predators. In this study we examine patterns of genetic structure in the broadnose sevengi...

Basking sharks (Cetorhinus maximus) were widely reported throughout New Zealand waters. Once commonly observed, and sometimes in large numbers, basking sharks are now infrequently reported. Basking shark observations are known to be highly variable across years, and their distribution and occurrence have been shown to be influenced by environmental...

Aim Despite the unprecedented rate of species redistribution during the Anthropocene, there are few monitoring programmes at the appropriate spatial and temporal scale to detect distributional change of marine species and to infer climate‐ versus human‐mediated drivers of change. Here, we present an approach that combines citizen science with exper...

Risks to deepwater chondrichthyans (sharks, rays, and chimaeras) from fishing are poorly understood, particularly in areas beyond national jurisdiction. We adapted productivity-susceptibility analysis (PSA) and sustainability assessment for fishing effects (SAFE) to assess the vulnerability of 173 deepwater chondrichthyans to various demersal fishi...

There remain parts of our planet that are seldom visited by humans, let alone scientists. In such locations, crowd-sourced or citizen scientist data can be critical in describing biodiversity and detecting change. Rangitāhua, the Kermadec Islands, are 750 km from the nearest human-habitation. Although our knowledge of this near pristine location ha...

Migratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking...

Effective ocean management and the conservation of highly migratory species depend on resolving the overlap between animal movements and distributions, and fishing effort. However, this information is lacking at a global scale. Here we show, using a big-data approach that combines satellite-tracked movements of pelagic sharks and global fishing fle...

• The national extinction risk of 103 New Zealand chondrichthyans (sharks, rays, and chimaeras), ~10% of the global chondrichthyan fauna, was evaluated for the first time using the International Union for Conservation of Nature Red List of Threatened Species Categories and Criteria. Across 32 families, 103 species were assessed. • New Zealand holds...

Many shark species are at risk of overexploitation due to their high economic value, slow maturation, and low recruitment compared to most teleosts. However, there is insufficient knowledge about population structure at different spatial scales necessary to optimise fisheries models. We used single-nucleotide polymorphisms (SNPs) obtained through c...

Pelagic sharks are vulnerable to overfishing because of their low reproductive rates, generally low growth rates, and high catch rates in tuna and billfish fisheries worldwide. Pelagic sharks often migrate long distances, but they may also occur close to shore, making it difficult to classify their behaviour on the continuum from oceanic nomad to c...

White sharks, Carcharodon carcharias, are often described as elusive, with little information available due to the logistical difficulties of studying large marine predators that make long-distance migrations across ocean basins. Increased understanding of aggregation patterns, combined with recent advances in technology have, however, facilitated...

In this paper we combine analyses of satellite telemetry and molecular data to investigate spatial connectivity and genetic structure among populations of shortfin mako (Isurus oxyrinchus) in and around Australian waters, where this species is taken in recreational and commercial fisheries. Mitochondrial DNA data suggest matrilineal substructure ac...

A population of the kelp Ecklonia radiata (Laminariales) has been found in mesophotic conditions at c. 72–80 m depth on the shelf surrounding Macauley Island, Rangitahua, Kermadec Islands (30 13.3'S, 178 23.8'W), in northern New Zealand, c. 900 km northeast of New Zealand on the western margin of the South Pacific Subtropical Gyre. This species was...

The conservation status of all known New Zealand chondrichthyan taxa (chimaeras, sharks and rays) was reassessed using the New Zealand Threat Classification System (NZTCS). Since the last assessment (in 2005), 9 new taxa have been added to the list, 6 have been removed from it and 30 have had name changes. Also, 1 previously Data Deficient taxon is...

New Zealand adopted a revised National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks 2013) in January 2014. Amongst other objectives, the NPOA-Sharks established a risk-based approach to prioritising management actions. An initial qualitative (level 1) risk assessment (RA) workshop in November 2014 assessed the risk to a...

Conservation concerns exist for many sharks but robust estimates of abundance are often lacking. Improving population status is a performance measure for species under conservation or recovery plans, yet the lack of data permitting estimation of population size means the efficacy of management actions can be difficult to assess, and achieving the g...

The application of genome-wide cytonuclear molecular data to identify management and adaptive units at various spatiotemporal levels is particularly important for overharvested large predatory organisms, often characterized by smaller, localized populations. Despite being “near threatened”, current understanding of habitat use and population struct...

The application of genome-wide cytonuclear molecular data to identify management and adaptive units at various spatio-temporal levels is particularly important for overharvested large predatory organisms, often characterized by smaller, localized populations. Despite being "near threatened", current understanding of habitat use and population struc...

Courtship behaviour of the giant devil ray Mobula mobular is described from northern New Zealand, temperate southwest Pacific Ocean, for the first time. A mating train consisting of a full term pregnant female and up to four males was observed over a period of 147 minutes. Their behaviour was similar to courtship behaviour observed in other large m...

The conservation and protection of marine megafauna require robust knowledge of where and when animals are located. Yet, our ability to predict animal distributions in space and time remains limited due to difficulties associated with studying elusive animals with large home ranges. The widespread deployment of satellite telemetry technology create...

The occurrence of the bignose shark Carcharhinus altimus at Ducie Island, Pitcairn Islands is reported for the first time based upon re-identification of four museum voucher specimens. The presence of a pregnant female and a juvenile confirms C. altimus breeds at Ducie Island and should be considered resident there. The specimens had been misidenti...

This paper provides a characterisation of the catch of chondrichthyans in New Zealand bottom fisheries in the SPRFMO Area and information on potential risks to deepwater chondrichthyan species from SPRFMO bottom fishing. Chondrichthyans, particularly those which predominantly occur or complete most of their lifecycle below 200 m depth, are known to...

Four observations of what was probably a single vagrant adult female whitetip reef shark Triaenodon obesus were made at Raoul and Meyer Islands, Kermadec Islands, New Zealand, over a 12 month period in 2014/15. This is the most southerly occurrence of the whitetip reef shark and ambient winter temperatures were close to the assumed thermal minimum...

Several international agreements and conventions require nations to establish Marine Protected Area (MPA) networks as an approach to alleviating biodiversity declines; however, a common problem in planning MPA networks is how to balance conservation objectives against economic objectives. Here, using the distributions of 102 biodiversity features a...

We use a genomic sampling of both nuclear and mitochondrial DNA markers to examine a pattern of genetic admixture between Carcharhinus galapagensis (Galapagos sharks) and Carcharhinus obscurus (dusky sharks), two well-known and closely related sharks that have been recognized as valid species for more than 100 years. We describe widespread mitochon...

Biodiversity of the Kermadec Islands and offshore waters of the Kermadec Ridge: report of a coastal, marine mammal and deep-sea survey (TAN1612) New Zealand Aquatic Environment and Biodiversity Report No. 179 Clark, M.R.; Trnski, T.; Constantine, R.; Aguirre, J.D.; Barker, J.; Betty, E.; Bowden, D.A.; Connell, A.; Duffy, C.; George, S.; Hannam, S.;...

The alpha taxonomy of the globally distributed shark genus Squalus has been under intense investigation recently, and many new species have been described over the last decade. However, taxonomic uncertainty remains about several taxa. Without consistent nomenclature and the ability to reliably distinguish between the different Squalus species, bas...

The alpha taxonomy of the globally distributed shark genus Squalus has been under intense investigation recently, and many new species have been described over the last decade. However, taxonomic uncertainty remains about several taxa. Without consistent nomenclature and the ability to reliably distinguish between the different Squalus species, bas...

Background Although widespread and intensively studied in the Southwest and Northeast Pacific Ocean, relatively little is known of the distribution and biology of the white shark (Carcharodon carcharias) Northwest Pacific. Results and conclusions Three underwater photographs of a large white shark taken near the St. Joseph oil field, Sabah, in 1981...

The occurrence of the sandbar shark Carcharhinus plumbeus at Norfolk Island is confirmed. Carcharhinus plumbeus occurs over the mid to outer insular shelf from 38 m to at least 53 m depth, and appears to be at least as abundant as C. galapagensis in this habitat. No C. plumbeus were caught from shore despite most fishing effort being land-based. Th...

Although primarily a coral reef species the grey reef shark Carcharhinus amblyrhynchos has been recorded from a number of subtropical oceanic islands and reefs in the Southwest Pacific Ocean. Examination of all nominal C. amblyrhynchos voucher material collected from Lord Howe Island, Elizabeth and Middleton Reefs and Norfolk Island resulted in the...

The sicklefin devilray Mobula tarapacana (Philippi, 1892) is one of the largest and least known mobulids (Compagno & Last 1999; Couturier et al. 2012). Collections, fisheries bycatch data and visual records suggest it is primarily oceanic, with a circumglobal tropical and warm temperate distribution (Notarbartolo-di-Sciara 1987; Compagno & Last 199...

Report to the New Zealand Department of Conservation on algal, marine invertebrate and fish collections made in the Kermadec Islands Marine Reserve during November 2004.

Marine mammals were observed on 46 occasions during two expeditions to the Kermadec Islands in 2004 and 2011. Species richness was greatest over the upper slope of the Bay of Plenty in May 2011, whereas abundance was greatest at the Kermadec Islands in November 2004. Diversity of cetaceans at the Kermadec Islands appears to be low however a systema...

Predation by yellowtail kingfish (Seriola lalandi) on a variety of seabirds is reported for the first time. These observations and a review of the available information indicate that at least eight species of seabird are taken by hapuku (Polyprion oxygeneios), snapper (Pagrus auratus) and yellowtail kingfish in New Zealand waters. Although predatio...

At least 2086 species from 729 families are reported from the insular shelf and upper slope of the Kermadec Islands Marine Reserve and north Kermadec Ridge. The best known groups are benthic Foraminifera, benthic macroalgae, Cnidaria, Mollusca, Crustacea, Bryozoa, Echinodermata, fishes and sea birds. However knowledge of the region’s biota remains...

The Kermadec Islands coastal fish fauna is still incompletely known, and recent expeditions there have added new fish records, and improved our understanding of its diversity and composition. This study documents 18 new fish records, presents an updated checklist of coastal fishes, and analyses the species biodiversity and biogeography. The coastal...

Five visits to the Kermadec Islands between 2004 and 2013 have increased the number of confirmed fish species from the region. The most intensive survey of shore fishes from all island groups of the Kermadec Islands was undertaken in May 2011. Additional fishes were recorded during surveys undertaken in 2004, 2012 and 2013. The main method used was...

Aim Underpinning conservation and management strategies at large spatial scales is the concept that spatial patterns of biodiversity are known, although this information is frequently lacking. Many countries routinely collect data on fish occurrence as part of stock assessments, and it has been suggested that this data could be a surrogate for othe...

Subadult and adult white sharks aggregate seasonally near pinniped colonies in several parts of the globe. The time spent there may represent the most vulnerable part of their otherwise migratory life cycle. White sharks have low productivity and may suffer population declines even when afforded legislative protection. White sharks were protected i...

This study assessed the levels of relatedness of Galeorhinus galeus of progeny arrays using six microsatellite DNA markers. A parentage analysis from five families (mother and litter) from the North Island of New Zealand suggested the occurrence of genetic polyandry in G. galeus with two of the five litters showing multiple sires involved in the pr...

Statistical models of the distribution and abundance of 72 species of rocky reef fishes were developed using boosted regression trees and a set of environmental, geographic and dive-specific variables. The models were used to predict and map the occurrence and relative abundance of the selected species on shallow coastal reefs around New Zealand, i...

Sawfishes (Pristidae) are large shark-like batoids with a distinctive flattened, greatly elongated rostrum armed on each side with a row of large transverse teeth. Two genera and at least four species occur in the Indo-West Pacific, of which Anoxypristis cuspidata (Latham, 1794), Pristis microdon Latham, 1794 and P. zijsron Bleeker, 1851 have wides...

The copper or bronze whaler shark (Carcharhinus brachyurus) is a large, coastal top predator that is vulnerable to overexploitation. We test the null hypothesis that copper sharks are panmictic throughout the southern hemisphere. We analysed part of the mitochondrial control region (mtCR) in 120 individuals from eight sampling areas, defining 20 mt...

The occurrence of great white sharks (Carcharodon carcharias) in New Caledonia is documented from 30 observation events (sightings or captures or forensic examination of wounds) made between 1943 and 2009, involving 34 individual sharks. Nine of the observation events concerned animals caught on lines set for deep-sea fishes, five were encounters w...

Recent advances in our understanding of the spatial behavior of white sharks have been based on only 3 geographical areas: the waters off Australia, southern Africa, and the northeast Pacific Ocean. Here we report results from the first study in New Zealand waters using satellite tags to study sharks. We attached pop-up archival tags to 4 white sha...

The occurrence of great white sharks (Carcharodon carcharias) in New Caledonia is documented from 30 observation events (sightings or captures or forensic examination of wounds) made between 1943 and 2009, involving 34 individual sharks. Nine of the observation events concerned animals caught on lines set for deep-sea fishes, five were encounters w...

We present a balanced model of organic carbon flows through a temperate coastal ecosystem in New Zealand. The Te Tapuwae o Rongokako Marine Reserve is a 2452 ha no-take area including both rocky reef platforms and soft sediment, and covering the intertidal and subtidal communities to depths of approximately 50 m. The model includes 22 trophic group...

There is strong international agreement on the need for marine protected areas to reverse pervasive human impacts on the oceans' biodiversity. However, their implementation is often hampered both by legal difficulties in defining reserves in international waters and the patchy nature of data in many offshore waters. We demonstrate the use of recent...

For many regions worldwide, multiple and often contrasting biogeographic classifications exist that are derived from a variety of taxa and techniques. This presents a challenge for managers who must choose appropriate large-scale spatial frameworks for systematic conservation planning. We demonstrate how systematically collected community data can...

The New Zealand Threat Classification System provides a tool for assigning a threat status to candidate taxa. In this revision of the 2002 system, substantial changes include the addition of the new categories ‘Declining’, ‘Naturally Uncommon’, ‘Recovering’ and ‘Relict’. The category ‘Naturally Uncommon’ is adopted to distinguish between biological...

Great whites – rovers or residents? New Zealand fishing news September 2007

Three specimens of Centrophorus from the southern Norfolk Ridge, three Kings Ridge, and Kermadec Ridge are provisionally identified as C. harrissoni, extending the species’ known range east to 178°52.1W. Although apparently rare, C. harrissoni is widely distributed in southern Australian waters and the southwest Pacific between 17°S and 43°S, occur...

The Northern Spiny Dogfish, Squalus griffini Phillipps, from central and northern New Zealand is resurrected based upon detailed re-examination of the holotype and new material collected from throughout its range. Comparisons are made with S. griffini and other large Indo–Pacific species of Squalus, including S. mitsukurii from the western North Pa...

Shark trek. Forest and Bird

Shortfin mako sharks were aged by counting growth bands in sectioned vertebrae (n = 256), and assuming annual band-pair deposition. No systematic ageing bias was present and count precision was high. 0+ juveniles were identified from length–frequency plots and assigned ages based on a theoretical birth date of 1 October and their date of capture. A...

Cetorhinicola acanthocapax Beveridge & Campbell, 1988 is redescribed based on adult specimens collected from a basking shark Cetorhinus maximus (Gunnerus) off the east coast of New Zealand. Both the mature and gravid segments are described for the first time, and the first scanning electron micrographs of the armature and scolex microtriches are pr...

Reproductive data collected from porbeagle, shortfin mako, and blue sharks caught around New Zealand were used to estimate the median length at maturity. Data on clasper development, presence or absence of spermatophores or spermatozeugmata, uterus width, and pregnancy were collected by observers aboard tuna longline vessels. Direct maturity estima...

Marine soft sediments are often considered to be vast, homogeneous expanses of mud or sand; however, most exhibit small-scale biogenic structures. Generally such structures result from short-term processes, but mollusk shell debris can last for centuries, providing a settlement surface for plants and animals, which in turn stabilize the debris. Thi...

On shallow temperate subtidal reefs, habitat types are usually defined subjectively by the dominance or presence of major macroalgal species. Many of these habitat types (e.g., urchin barrens, kelp forest) are frequently used in the literature but little attempt has been made to quantitatively define these habitats. A survey of shallow subtidal ree...

Data from 31 sightings of mobulid rays from New Zealand are summarised. Mobulid rays are common to locally abundant off north‐east North Island, New Zealand during summer and early autumn. Collection records and sightings data indicate the spine‐tailed devil ray (Mobula japanica) is the most abundant mobulid in New Zealand waters. Photographic and...

Data from 36 whale shark (Rhincodon typus Smith, 1828) sightings off north‐east North Island, New Zealand are summarised. Sightings were concentrated over the outer shelf and shelf break in areas influenced by the East Auckland Current at sea surface temperatures (SST) of 21–24°C. Sightings occurred from late spring to early autumn (November‐April)...

Basking sharks occur throughout New Zealand, but are most common in cool temperate latitudes of 39-51S. Inshore records from miscellaneous sources peaked in spring-summer, with few winter records. Two records were of sharks observed in a large brackish water lake. About 203 basking sharks were observed caught by commercial trawlers between 1986 and...

In some respects, these sharks behave more like whales and dolphins than other fish.

A litter of eight near‐term shortfin mako (Isurus oxyrinchus Rafinesque 1810) embryos is described from a 317.5 cm total length (TL) female caught off Hawke Bay, south‐east North Island, New Zealand on 5 February 1999. The embryos (3 males and 5 females) were 67.2–77.0 cm TL. Embryo length, condition, hepato‐somatic indices, and mass of yolk in the...

Epipelagic juvenile bluenose, Hyperoglyphe antarctica (Carmichael 1818), are recorded from New Zealand for the first time. Two specimens were collected beneath flotsam nearNga Motu/Sugar Loaf Islands, west coast North Island in September 1996, and at least 20 were found inside a piece of trawl net drifting east of Cape Kidnappers, east coast North...

Epipelagic juvenile bluenose, Hyperoglyphe antarctica (Carmichael 1818), are recorded from New Zealand for the first time. Two specimens were collected beneath flotsam nearNga Motu/Sugar Loaf Islands, west coast North Island in September 1996, and at least 20 were found inside a piece of trawl net drifting east of Cape Kidnappers, east coast North...